> When is the first recorded mention of understanding that sunrise is not
> simultaneous worldwide?
As has already been mentioned, anybody educated has known that the Earth is round since at least the time of the ancient Greeks. Anyone who knows that also knows that sunrise is not simultaneous around the Earth. Perhaps there are some ancient writings that discuss sunrise in different places where the writer doesn’t know that the Earth is round, but I can’t think of any such writings.
Right. My roomate seemed to think it was just provincial stubborness on the part of people in the Pacific Time Zone that prevented them from getting with the program and synchronizing their clocks to the Eastern Time Zone, thereby experiencing noon when the sun was only part way up in the sky.
Once we get the subterranean arcologies set up, everyone’s watches will be set to Greenwich Time, and the actual position of the Sun in the sky will be of interest to only a few people. The general population will care no more for the “local time” than the average citizen now cares about the tides.
I’m not convinced that "the Earth is round’ is all that great of an explanation, either. It takes a few more steps to figure out what is going on, and it still leaves some mysteries (how can one Hawaiian island have desert and the wettest place on Earth at the same time?)
For the most part I bet they did what we do now- not worry too much about it.
Anyway, comparisons would rarely come up. Travel took long enough that changes in climate would be pretty gradual, and communication across long distances was very limited. Today we know a lot about other climates because we watch weather reports, talk to people long distance and read books about other places. But how much do you know about the springtime weather in, say, the Cape Verde? That’s about how much a Londoner would know about the weather in Rome.
Which is a somewhat defensible opinion, not ignorance of the fact that sunrises aren’t synchronized. I’ve been known to state myself that we should just do away with the concept of time zones, along with attendant DST corrections, and have everybody use UCT. Your local sunrise might be at 1:00 PM. So what? Office hours around here would typically be 1 AM to 9 AM. Fine. I wouldn’t have to keep performing mental base 24 arithmetic with a stupid AM/PM convention to convert somebody else’s time to mine. If we wished to make better use of daylight hours during summer months, seasonally change business hours, NOT the clocks.
(Yes, I’m aware that AM and PM mean “ante” and “post” meridian. They wouldn’t represent the first meaningless conventions preserved in the language for historic reasons. Again, so what? Going to 24 hour time, or decimalizing the whole bloody business are topics for later proposals.)
Yabob so instead of remembering that California is three hours behind the east coast you will have to remember that the sun rises about 3 hours later in California and peoples’ schedules tend to be adjusted by about 3 hours between the two places. Sounds like the same amount of math and memorization to me.
For things where you care about other people’s schedules, yeah, it’s about the same amount of work. But it gets you out of having to convert when some event is announced to occur at “2:30 PM EST”, and you want to know when to turn on the news.
Heck, my dad, born and raised in the Pacific time zone, said that when he joined the Marines in 1963 and did basic training in San Diego he met fellow recruits from the East coast who believed we were still fighting the Indian Wars out here.
Well, you never met my former roomate but it’s possible he WAS ignorant of the fact that sunrises aren’t synchronized. Not the sharpest knife in the drawer.
I really couldn’t figure out, then or now, exactly how he pictured the whole business actually worked.
G-d d—it! I read all the way through this thread, itching with the anticipation of making precisely this point, and you beat me to it by twenty minutes.